Marina Donária Chaves Arantes

Effect of age and diameter class on the properties of wood from clonal Eucalyptus

The objective of this work was to evaluate the influence of age and diameter class on the physical, thermal and chemical characteristics of a clone of Eucalyptus grandis and Eucalyptus urophylla. The material originated from a reforestation site owned by GERDAU S.A. and included trees at age 34, 48, 61, 74 and 86 months. Two trees were selected per age in each diameter class, observing the proportion of each established plot. Analyses of physical characteristics included wood basic density, dry matter weight and carbon stock, and of chemical characteristics included holocellulose, total extractives content, total lignin and ash content, in addition to elemental and thermal analysis of the wood. Results led to the conclusion that most wood properties were influenced by age and diameter class. The species was found to have great potential for production of biomass and generation of heat energy, potentially convertible into mechanical energy and electricity.

CARACTERÍSTICAS ANATÔMICAS E PROPRIEDADES FÍSICO-MECÂNICAS DAS MADEIRAS DE DUAS ESPÉCIES DE MOGNO AFRICANO

The objective of this study was to evaluate the anatomical characteristics and wood physical-mechanical properties of two African mahogany species (Khaya ivorensis and Khaya senegalensis). Five trees of each species with 19-years-old, proceeding from experimental parcels in the areas of the Reserva Natural Vale, located in Sooretama, Espirito Santo State, Brazil. For the anatomical characteristics samples were taken at the position of transition between heartwood and sapwood (peripheral heart). In the evaluation of the specific density were used two opposing wedges from discs gotten in the corresponding region to the diameter the height of the breast (DHB), taken the 1,30 m of the ground, and in positions 0, 25, 50, 75 and 100% of the commercial height of the tree. For shrinkage 20 samples obtained randomly throughout the trunk of each species. The mechanical tests were carried through in removed samples of the central large plank, to the discarded the pith. The species were different how much to the type and frequency of vases and porosity. Rays were predominantly multiseriates, heterocellulars and fibers are libriform. The wood of Khaya ivorensis has low specific density and wood of Khaya senegalensis has medium specific density. The two wood species have normal dimensional stability. In relation the mechanical properties, the Khaya senegalensis wood had the biggest values for all the carried through tests.

Características do carvão de um clone de Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake

Neste trabalho, objetivou-se determinar a variabilidade existente nas caracteristicas do carvao de um clone de Eucalyptus grandis x Eucalyptus urophylla aos 6 anos, plantado no municipio de Martinho Campos, MG. As arvores foram distribuidas em tres classes de diâmetro e a amostragem consistiu na retirada de discos, de 2,5 cm de espessura, a 2%, 10%, 30% e 70% da altura comercial, alem de um a 1,30 m do solo (DAP) e, a partir deste ponto, de metro em metro ate a altura comercial. Foram tomadas amostras ao longo do raio nos discos, considerando os dois lados em relacao a medula. As amostras foram carbonizadas em forno eletrico de laboratorio, sendo determinados os rendimentos e a qualidade do carvao vegetal produzido. Pelos resultados, verificou-se que para a primeira carbonizacao, a classe diametrica influenciou significativamente o rendimento gravimetrico em carvao vegetal, em liquido pirolenhoso e o teor de cinza do carvao vegetal produzido, e que o rendimento em gas nao condensavel, o teor de materiais volateis e o de carbono fixo nao foram influenciados pela classe diametrica; para a segunda carbonizacao o rendimento gravimetrico aumentou da casca para a medula, para todas as classes diametricas e ocorreu reducao dessa caracteristica com a diminuicao das classes diametricas e que os valores de densidade relativa aparente tenderam a aumentar no sentido medula-casca, em todas as classes diametricas.

Longitudinal and radial variation of extractives and total lignin contents in a clone of Eucalyptus grandis W.Hill ex Maiden x Eucalyptus urophylla S. T. Blake

The objective of this work was to determine concentrations of extractives and total lignin along with their radial and longitudinal variations in wood from a clone of Eucalyptus grandis W.Hill ex Maiden x Eucalyptus urophylla S. T. Blake at age six years. Longitudinal samples were taken at 2%, 10%, 30% and 70% of the commercial height of trees, and radial samples were taken from each longitudinal position, the number of samples depending on the diameter of each disk. Results led to the conclusion that, overall, concentrations of extractives and total lignin in the wood tended to decrease with increasing distance from the pith and tended to increase in portions closer to the tree base.

RESISTÊNCIA DE DUAS ESPÉCIES DE BAMBU TRATADAS CONTRA FUNGOS XILÓFAGOS

This work aimed to evaluate the resistance of bamboo species Bambusa vulgaris and Dendrocalamus giganteus, after being exposed to three methods of chemical preservative treatments against the action of Postia placenta and Polyporus fumosus fungi. The treatment methods employed were transpiration (integral and ruptured diaphragm), long-term immersion and Boucherie modified. The bamboo stems were transformed into culms of 2.0 m long and treated in a solution of 1 or 3% active ingredient (a.i.) of a commercial product based on copper, chromium and boron (CCB). In the methods by transpiration and the long-term immersion, culms were exposed in solutions for periods of 5, 10 or 15 days, while in the modified Boucherie method there was no segregation of treatment between times of treatment. To assess the effectiveness of the treatments, Postia placenta and Polyporus fumosus fungi were employed. From the results obtained it was observed that, on average, for both species of bamboo and tested methods, the mass loss of samples of bamboo, after undergoing the fungal attack, was low, varying from 2.44 to 14.26%.O objetivo deste trabalho foi avaliar a resistencia de bambus das especies Bambusa vulgaris e Dendrocalamus giganteus apos serem expostos a tres metodos de tratamentos quimicos preservativos, contra a acao dos fungos Postia placenta e Polyporus fumosus. Os metodos de tratamento empregados foram o de transpiracao (diafragma integro e rompido), imersao prolongada e Boucherie modificado. As hastes de bambu foram transformadas em colmos de 2,0 m de comprimento e tratadas em solucao de 1 ou 3% de ingredientes ativos (i.a.) de um produto comercial a base de cobre, cromo e boro (CCB). Nos metodos por transpiracao e imersao prolongada, os colmos foram expostos nas solucoes por periodos de 5, 10 ou 15 dias, enquanto no metodo de Boucherie modificado nao houve segregacao do tratamento entre tempos de tratamento. Para avaliar a eficiencia dos tratamentos, foram empregados os fungos Postia placenta e Polyporus fumosus. A partir dos resultados, observou-se que, em media, em ambas as especies de bambu tratadas e metodos empregados, a perda de massa das amostras de bambu, depois de submetidas ao ataque dos fungos, foi baixa, tendo variado de 2,44 a 14,26%.

ENERGY ESTIMATE AND CARBON STOCK IN SHORT-ROTATION EUCALYPTUS STANDS

A utilizacao da biomassa como fonte de energia alternativa tem obtido destaque por suas caracteristicas energeticas, contribuicao ambiental e por ser fonte de energia renovavel em curto periodo de producao. O trabalho objetivou avaliar a producao da biomassa e sequestro de carbono de eucalipto em diferentes condicoes de crescimento. Foram determinadas a densidade basica da madeira, volume individual com e sem casca, biomassa seca, carbono acumulado, dioxido de carbono assimilado e estimativa energetica dos componentes da parte aerea de dois clones do hibrido de E. grandis x E. urophylla aos 6 e 12 meses de idade, em diferentes espacamentos e provenientes de duas areas, uma irrigada e outra nao irrigada. Os maiores valores de biomassa seca e massa de carbono foram provenientes dos clones nos espacamentos mais adensados e regiao irrigada. O efeito da irrigacao foi significativo nas variaveis estudadas apenas nos clones com 12 meses. A quantidade de CO2 assimilada no fuste, folha e galho foram maiores nos espacamentos mais amplos e regiao irrigada dos clones com 12 meses. A estimativa energetica do fuste aumentou com a ampliacao do espacamento. Entre os componentes arboreos, a casca sofreu menor influencia dos espacamentos e irrigacao.

EFEITO DO ESPAÇAMENTO, DA IDADE E DA IRRIGAÇÃO NOS COMPONENTES QUÍMICOS DA MADEIRA DE EUCALIPTO

The objective of this study was to evaluate the influence of age, irrigation and spacing on the chemical composition of eucalyptus wood. The materials used were two clones of Eucalyptus grandis x Eucalyptus urophylla, ages of 6 and 12 months, from planting in two regions, one irrigated and the other not irrigated, with spacings of 3 x 0.5; 1.5 x 2; 3 x 1; 3 x 2; and 3 x 3 meters. In the chemical analysis of the wood, a sampling was conducted composed of six discs obtained along the tree trunk. At the end of this study, it was possible to notice the influence of age, spacing and irrigation in the chemical composition of the wood, and that the content of holocellulose did not follow trend pattern, with different results for each treatment. Higher values of extractives content occurred in non-irrigated clones and aged six months, with no influence of spacing. The major results of lignin content were obtained in greater spacings, although results tendency of lignin content was not seen for age and irrigated treatment. The ash content was higher at the age of six months and there was no results tendency for different spacings and regions.

Tratamento Preservativo de Duas Espécies de Bambu por Imersão Prolongada e Boucherie Modificado

This study aimed to evaluate the quality of preservative treatment of Bambusa vulgaris and Dendrocalamus giganteus bamboo species employing two treatment methods. The bamboos were collected in clumps in the municipalities of Alegre and Jeronimo Monteiro, southern of Espirito Santo State, Brazil. The stems were sectioned in 2.0 m-long culms and treated in solutions with 1 and 3% of the active ingredients (a.i.) of a product based on copper, chromium and boron (CCB). In the long-term immersion method, the culms were immersed in the solution for 5, 10 and 15 days. In the modified Boucherie method, the solution penetrated the bamboo species using a pressure of 0.7 MPa. Treatment quality was evaluated by means of penetration and retention of CCB in the culms. There was greater penetration of a.i. at the base of the culms, and retention was below recommendation according to the Brazilian standards for wood treatment.

Tratamento Preservativo de Duas Espécies de Bambu por Imersão Prolongada e Boucherie Modificado / Preservative Treatment of Two Bamboo Species by Long-Term Immersion and Modified Boucherie

This study aimed to evaluate the quality of preservative treatment of Bambusa vulgaris and Dendrocalamus giganteus bamboo species employing two treatment methods. The bamboos were collected in clumps in the municipalities of Alegre and Jeronimo Monteiro, southern of Espirito Santo State, Brazil. The stems were sectioned in 2.0 m-long culms and treated in solutions with 1 and 3% of the active ingredients (a.i.) of a product based on copper, chromium and boron (CCB). In the long-term immersion method, the culms were immersed in the solution for 5, 10 and 15 days. In the modified Boucherie method, the solution penetrated the bamboo species using a pressure of 0.7 MPa. Treatment quality was evaluated by means of penetration and retention of CCB in the culms. There was greater penetration of a.i. at the base of the culms, and retention was below recommendation according to the Brazilian standards for wood treatment.

Influência de compostos de boro nas propriedades físicas da madeira de Eucalyptus sp.

A madeira quando em uso tem se mostrado susceptível ao ataque de besouros e cupins, sendo tal ataque economicamente prejudicial ao homem. E, para impedir tal degradação indesejável, atualmente faz-se do uso de diversos preservantes químicos, os quais se destacam os compostos de boro. Desse modo, o objetivo desta pesquisa foi identificar a influência dos compostos de boro na densidade básica e contração da madeira de Eucalyptus sp. e, a eficiência do tratamento preservante. Foram usados 160 corpos-de-prova com dimensões de 2 x 2 x 5 cm, provenientes de resíduos madeireiros, onde 80 amostras foram tratadas com o preservante e outros 80 não receberam tratamento. Após o tratamento de impregnação à vácuo, realizou-se o teste qualitativo para avaliar a penetração do preservante na madeira tratada, bem como os ensaios de densidade e contração nas amostras com ou sem preservante. Os resultados indicaram que a maior penetração na madeira tratada com compostos de boro foi a nível parcial irregular e, que o tratamento preservante aumentou significativamente a densidade básica da madeira tratada, em relação a não tratada. E, os valores médios de contração total na madeira tratada foram inferiores em 17,5%, 14,8% e 15,5%, para contração tangencial, radial e volumétrica, respectivamente, em relação a madeira não tratada. Desse modo, observou-se que o boro afetou significativamente as propriedades físicas, analisadas, da madeira. Palavras-chave: Contração; Ácido bórico; Densidade básica; Tratamento preservante;